NA TURE 



8i 



THURSDAY, DECEMBER 2, 1875 



THE GOVERNMENT AND THE POLLUTION 

 OF RIVERS 



Pollution of Rivers. What Means can be adopted to 

 prevent the Pollution of Rivers ? A Paper read at 

 the Social Science Congress, Plymouth and Devonport, 

 September 1872, by William Hope, V.C. (London, 



1873-) 

 food Manufacture versus River Pollution. A Letter 

 addressed to the Newspaper Press of England, by the 

 same Author. (London : Stanford, 1875.) 



THE question of River Pollution, one of undoubted 

 importance to the country at large, has been once 

 again raised by Mr. Hope, so well known for his untiring 

 zeal in the cause of sewage farming, in the two above- 

 named pamphlets. As involving questions of science — 

 or at least of applied science — we feel called upon to 

 offer some remarks upon the subject, the more so as it is 

 one having such unquestionable sanitary bearings as to 

 have been made the subject of Select Committees, Royal 

 Commissions, and of at least three Parliamentary Bills. 



We shall in the first place give a brief abstract of Mr. 

 Hope's pamphlets, in order to lay before our readers the 

 present state of the sewage question, before proceeding 

 to consider the manner in which the subject has been 

 handled by the Legislature. 



In the first-named pamphlet the author passes in review 

 the chief processes which have been proposed for pre- 

 venting the pollution of rivers by sewage, classifying all 

 systems under two divisions — "those which profess to deal 

 with part only of the sewage, and those which profess to 

 deal with the whole." The inefificacy of the former is 

 summed up in the following words (page 5) : — 



" But supposing that they really accomplished all they 

 are intended to effect, the sewage question would still be 

 as far from solution as ever, for the part of the total refuse 

 which they profess to deal with is only about a half per 

 cent, of the whole." 



Of processes professing to deal with the whole of the 

 sewage the first noticed are those precipitation schemes 

 in which the sewage matter is supposed to be precipitated 

 by the addition of some chemical substance. The so- 

 called " A B C" process is considered at some length, and 

 its not very creditable history traced ; analyses of the 

 various precipitating mixtures employed by this company 

 are given, beginning with that first employed which the 

 author distinguishes as " Moses " (because stated by the 

 patentee to have been first revealed to Moses in the wil- 

 derness and communicated by him to the children of 

 Israel I), and concluding with that in use at Leeds at the 

 time of reading the paper. 



When we state that this mixture consists of alum, 

 blood, clay, and charcoal refuse from Prussian blue 

 works, our readers will at once perceive the justice of the 

 sentence pronounced by Mr. Hope — that none of the 

 ammonia in solution is precipitated, but runs away in the 

 effluent water. We may furthermore recall to mind the 

 fact that the process as carried on at Leicester and 

 Leamington, with a mixture containing the same ingre- 

 dients in different proportions, was made the subject of 

 an exhaustive inquiry by the Rivers Pollution Commis- 

 VoL. XIII.— No. 318 



sion, and justly condemned by that body in their second 

 Report, on the grounds of its failing to remove the organic 

 polluting substances in the state of solution. The same 

 objections are applicable to Forbes' phosphate of alumina 

 process, and to Anderson's process, which are the next 

 considered. Mr. Whitthread's phosphate of calcium pro- 

 cess is spoken of somewhat more hopefully, although at 

 the time of reading the paper it was in a very early stage 

 of development, while Weare's peat charcoal process is 

 unhesitatingly condemned — " the effluent water resulting 

 from it is, as a matter of fact, still sewage." 



General Scott's hydraulic cement process, which con- 

 sists in precipitating lime and clay in the sewage, is effec- 

 tive in clarifying and to a great extent deodorising the 

 sewage by the removal of suspended matters in the form 

 of " sludge," but from a sanitary point of view the sewage 

 question is untouched, as the inventor does not profess to 

 deal with the effluent water. 



The purification of sewage by its direct application to 

 land as effected by irrigation next receives consideration, 

 the author pointing out that this is really an effective 

 means of disposing of sewage — a statement fully borne 

 out by every scientific authority who has examined into 

 the method. Without at present entering too fully into 

 details, we may state that the author's experience has led 

 him to the conclusion that the successful treatment of 

 sewage as a manure depends upon its thorough inter- 

 mittent downward filtration through the soil, with due 

 precautions against overflooding the land. By those who 

 have followed the question from the beginning, it will be re- 

 membered that the chemical principles of " downward in- 

 termittent filtration" were first discovered in the laboratory 

 of the Rivers Pollution Commission, and its efficiency 

 made known in their first Report. The chemistry of the 

 process, it is scarcely necessary to add, is accelerated 

 oxidation, and Mr. Hope had been independently led to 

 adopt this principle as appUed to irrigation on an experi- 

 mental sewage farm at Romford. The remainder of the 

 pamphlet is chiefly devoted to what we cannot but con- 

 sider as a fruitless discussion upon the precise meaning 

 ■ of the terms " irrigation " and " intermittent downward 

 filtration," it being contended that the two processes are 

 really identical — an opinion in which we feel constrained 

 to differ from the author, since, although the involved 

 principles are most probably the same, the methods of 

 appH cation are essentially different. The results of the early 

 experiments upon the Romford farm were made known 

 to the British Association Committee at the Brighton 

 meeting, and are thus summarised by the author : — 



"Although the soil is exceedingly siliceous, and ill- 

 adapted for the retention of manure, yet out of every 100 

 parts of nitrogen applied in the sewage, no less than 40 

 were actually converted into crops, 50 parts were unac- 

 counted for (remaining chiefly in the soil), and only 10 

 parts escaped in the effluent water, of which again only a 

 fraction was still in an organic form." 



The second pamphlet is a spirited appeal to the press 

 to take up the sewage question, but as it relates chiefly to 

 the financial aspect of the matter, it is not well adapted 

 for abstracting in these columns. It may be stated, how- 

 ever, that the author therein admits that he has met with 

 hea^'y losses in the working of the Romford farm, because, 

 in his own words, " he has not had the sewage of Romford 

 to convert." The original outlay, it seems, had been based 



